Laugh out loud comedies?

Alright, I know everyone's taste in comedies varies, but I need some recommendations for my father-in-law. His only request for Christmas is funny DVD's. I myself like "Mallrats", but he likes more straight forward comedies. Any help would be greatly appreciated. Chris

I found that Liar Liar appealed to even the non-Carrey lovers. I laughed out loud several times. If he likes some of the classics, Some Like It Hot is a scream. Here are some other honorable mentions:
Caddyshack
Home Alone
The Princess Bride

If he's more into comedies a little older, I know a few that still have me laughing out loud when I see them:
It's A Mad, Mad, Mad, Mad World
Dr. Strangelove
Yours, Mine, And Ours (Of course, it helps if you come from a big family.)
Duck Soup
Harold & Maude
And I definitely second Some Like It Hot.

Reviewer

"The Producers" is being released on DVD tomorrow.
Those early Woody Allen movies like "Sleeper" and "Bananas" are also pretty funny.
Some pretty reliable classic comedies are "It Happened One Night", "His Girl Friday", "Some Like it Hot", and "Sullivan's Travels".
For more recent stuff, I liked "Bowfinger" and "Meet the Parents". The latter might be either an especially appropriate or especially inappropriate choice depending on your relationship with your father-in-law.
Oh, and in the interest of full disclosure I will admit that I laughed my head off at "Tommy Boy" on more than one occasion.
Regards,

Although it is great, you have to be weary of The Big Lebowski, I've now had quite a few "white russian nights" while watching this flick.
Yours, Ours, and Mine is also a classic.
And I must admit watching the Ladies Man made me laugh. Or maybe it was just the way we all imitated his character afterwards.

I certainly don't expect anyone to remember me 65 years after I die, but you wouldn't know that from the way I act.

A Shot In The Dark Arsenic and Old Lace City Lights Some Like It Hot Harvey It's A Mad Mad Mad Mad World A Hard Day's Night Singin' In The Rain Modern Times The Circus The Great Dictator The General Sherlock Jr. The Producers

As for some not on DVD...but still hillarious:

Pack Up Your Troubles (Laurel and Hardy) The Sin Of Harold Diddlebock (AKA Mad Wednesday) Safety Last Duck Soup Sons of the Desert